Forgot your password?
typodupeerror
Power Science

The Potential of Geothermal Power 397

Posted by Zonk
from the much-better-than-burning-goo dept.
EskimoJoe wrote with a link to an AP article about progress in the development of geothermal energy. A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant. The concept is simple to understand: earth's core heat transforms water into steam, which in turn causes a turbine to revolve. The potential, though, is enormous. "Scientists say this geothermal energy, clean, quiet and virtually inexhaustible, could fill the world's annual needs 250,000 times over with nearly zero impact on the climate or the environment. A study released this year by the Massachusetts Institute of Technology said if 40 percent of the heat under the United States could be tapped, it would meet demand 56,000 times over. It said an investment of $800 million to $1 billion could produce more than 100 gigawatts of electricity by 2050, equaling the combined output of all 104 nuclear power plants in the U.S."
This discussion has been archived. No new comments can be posted.

The Potential of Geothermal Power

Comments Filter:
  • Misleading (Score:5, Informative)

    by Remusti (1131423) on Sunday August 05, 2007 @04:42AM (#20119615)
    The summary is misleading, Geothermal power [wikipedia.org] plants already exist.
    • by vtcodger (957785)
      ***The summary is misleading, Geothermal power plants already exist***

      The article mentions that in fact. I think they meant the first geothermal plant using deliberately injected water as opposed to heated water/steam that occurs naturally.

      • by gringer (252588)

        I think they meant the first geothermal plant using deliberately injected water as opposed to heated water/steam that occurs naturally.

        Oh, right. I get you now. You mean something like this:

        http://www.nzgeothermal.org.nz/geothermal_energy/n z_geothermal_fields.asp#Wairakei_Tauhara [nzgeothermal.org.nz]

        Separated water from the Wairakei field is used to provide fluids for the Netcor tourist facility, and a heat source for a prawn farm adjacent to the Wairakei power station. About half of the separated water is now reinjected and half is discharged to the Waikato River.

        Or...

        The station currently generates around 200 GWh per year. About half of the steam condensate is reinjected while the remainder is discharged to air through the cooling towers.

        Then again, having not read the article, I suppose this could be describing injection into dry rock, which then means that it's not possible to (initially) use water that didn't originate at the heat source.

        • Re:Misleading (Score:4, Interesting)

          by ozmanjusri (601766) <aussie_bob@hotmail.cOPENBSDom minus bsd> on Sunday August 05, 2007 @06:06AM (#20119949) Journal
          Then again, having not read the article, I suppose this could be describing injection into dry rock

          It includes injection, but the key part is drilling into hot parts of the earth's crust, fracturing the rock, then injecting water into the fractured rock and harvesting the steam.

          Both the summary and TFA are a little misleading. HDR is being tested in many parts of the world, including Japan, France, Australia and the US. The Australian site is here; http://www.geodynamics.com.au/IRM/content/home.htm l [geodynamics.com.au].

          It's a promising approach to clean power generation, but it won't work everywhere. HDR relies on a steeper than normal thermal gradient. Temperature rises with depth at a rate of about 20c/km on average, so hole depths without the steep gradient are too great for power generation to be economically feasible.

          • Re: (Score:3, Interesting)

            by OddesE (1100455)
            If they dump excess heat in a nearby river it has a very real environmental impact. Lot's of fish get into trouble if the water they live in rises in temperature too much. In holland we have had a few occasions where the national grid operator, TenneT, gave a 'code red' because electricity supply was becoming endangered, because power plants could no longer dump excess heat in the rivers because the temperature got too high. At some point they can't dump the heat anymore and have to shut down.
            • Re: (Score:3, Insightful)

              by ozmanjusri (601766)
              If they dump excess heat in a nearby river it has a very real environmental impact.

              Perhaps, but;

              1. The Geodynamics project is in the middle of a desert in South Australia. The nearest river is hundreds of kilometres away.
              2. That heat is energy. The HDR system uses that energy to turn turbines, and recycles the water back down the bore. There is no excess.
              Excess heat is as relevant to a HDR generator as CO emissions are to an electric motor.
              • Re: (Score:2, Insightful)

                by RobRyland (960596)
                I call BS. Go look up the Carnot engine. it defines the maximum theoretical effeciecy for converting thermal energy to non-thermal energy. there is ALWAYS excess. Now, a geothermal plant located near the ocean (or even on a platform 30 miles offshore) could use a much larger (and colder) heatsink. -Rob
    • Re: (Score:2, Insightful)

      No, the summary said a "Swiss company is competing ... to be the first to commercially develop a geothermal power plant," which is nearly word-for-word what the actual article said. The article reveals almost nothing, unfortunately. The Wikipedia article to which you linked isn't clear, but the few geothermal plans mentioned in it seem to be spotty efforts, not a large-scale one. The corporation that owns most of the existing plants isn't doing too well in terms of stock price, so I'm assuming that's what "
      • Re:Misleading (Score:5, Informative)

        by blowdart (31458) on Sunday August 05, 2007 @05:39AM (#20119847) Homepage
        Spotty effects? Iceland's geothermal power plants provide 26% of the power there (the majority is from hydroelectric), plus geothermal heating plants heat around 87% of homes. On the other hand the baths and showers I had there did stink of sulphur.
        • by notnAP (846325)
          How does the method of heating water affect the smell of water, outside of having major leaks in your water heater?
      • The Wikipedia article to which you linked isn't clear, but the few geothermal plans mentioned in it seem to be spotty efforts, not a large-scale one. The corporation that owns most of the existing plants isn't doing too well in terms of stock price, so I'm assuming that's what "commercial" is referring to, that there's been a breakthrough in profit-making in the area of geothermal power generation.

        Well, the nation of Iceland uses geothermal energy for more than half of its total primary energy input, incl

      • Re: (Score:3, Interesting)

        by Courageous (228506)
        Capitalism in action. Fuck the environment unless it makes you money.

        All capitalism really does is reflect popular sentiment through a kind of voting system.

        Consider:

        Many years back I was speaking with a coworker of mine about Green Mountain Energy, here in California. The price was essentially the same as local power, although occasionally more expensive. I had switched to Green Mountain. My coworker said that she'd looked into it, and that it wasn't worth the price.

        The catch? I knew my coworker to be what
    • by loganrapp (975327)
      Going Geothermal isn't worth the time. Not if you want to Flash rush the Core's Commander.
      • I think investing in a few Fusion power plants should do that trick, thought I go for the expensive option of cloaking them at the same time.
  • by saibot834 (1061528) on Sunday August 05, 2007 @04:42AM (#20119619) Homepage
    I don't know if this method is supposed to be much more eco-friendly, but to me it sounds like that would make it much warmer up here, on the earth's surface...
    • Re: (Score:2, Insightful)

      by Sproggit (18426)
      Actually it would make it cooler, since that energy was already heat, and we are changing it to electricty....
      • by zCyl (14362)

        Actually it would make it cooler, since that energy was already heat, and we are changing it to electricty....

        Attention. You have just violated a law of thermodynamics. Please report for sentencing.
        • Re: (Score:2, Interesting)

          by Sproggit (18426)
          Nope, no violations here officer.
          The amount of cooling of the crust would equate (minus inefficiencies) to electricity produced.
          This electricity would be converted to other forms of energy (and ultimately, more heat, I suspect).

          Total overall energy in closed system would therefore remain constant, and thermodynamic laws are satisifed.

          OK?
    • But it sounds like that is what they're proposing. As far as I'm aware, the natural flow of geothermal energy from below the surface is only 45 TW [altenergyaction.org], and the world already using close to 15 TW, so the total available is 3 times world energy use, not 250,000 times ???
      • As far as I'm aware, the natural flow of geothermal energy from below the surface is only 45 TW

        I suppose it depends on how deep you want to dig.

    • by gravos (912628)
      Not to mention cooler in the core.

      Would geothermal plants cause environmental problems if huge numbers were built? Almost definitely. Probably the best way to reduce overall impact from any one type of power plant is to always a mix of all the different types (solar, wind, tidal, geothermal, etc)--at least that way if one kind causes damage that we don't yet understand, the damage is more limited than if we used that method for 100% of our power generation.
    • Re:Global Warming? (Score:5, Interesting)

      by Scooter (8281) <owen&annicnova,force9,net> on Sunday August 05, 2007 @05:13AM (#20119759)
      I guess we already "make" this heat to power the turbines in power stations(i.e. we transform other types of energy into heat), so I would be inclined to say that using geothermal power would not result in a net increase of heat output on the surface. Unless perhaps, that that now guilt-free and cheap electricity causes everyone to go on a leccy binge for the next 200 years and consumption goes through the roof.

      I recently visited Iceland where they use the country's ample supply of superheated steam to produce electricity (and provide hot water and heating). A related question that sprang to mind was "if the rest of the world did this, what would be the effects of letting all that heat out? Would the amount of heat that we would cause to escape from the planet's core be significant? We need a geophysicist to give a proper answer to that - but I'm a suspicious bugger and all this "free" electricity looks too good to be true - you know what they say about free lunches. Essentially, we'd be using the planet like a battery: it's just a question of how long it will last - millions of years? Thousands?

      One of the other things that struck me about what the Icelanders are doing, is that they may just have struck their country's equivalent of oil. In the past, they couldn't really export their natural resource - steam goes off quite quickly. Then, they figured out how to make electricity with it, which is a bit easier to store and transport, but not out of the country. Now though, it looks like there may soon be a large world market for hydrogen, if fuel cells and other hydrogen consuming automotive engines take off. Iceland has all the ingredients to produce it - seawater, and abundant electricity. There are a number of problems to overcome in transporting it safely, but I reckon these guys may soon be rolling in it.

      The Shell petrol station in Reykjavik already sells hydrogen. It's not clear who to exactly right now, but Shell obviously believes it has a future.
      • by evilviper (135110)

        Now though, it looks like there may soon be a large world market for hydrogen, if fuel cells and other hydrogen consuming automotive engines take off. Iceland has all the ingredients to produce it - seawater, and abundant electricity.

        Iceland has the ingredients. However, the people who live there aren't too happy about factories being built over every geothermal vent in sight. They recently put a stop to Alcoa's expansion plans for that very reason.

        Here in the US, we have quite a bit of geothermal vents a

  • 100 / 1.21 (Score:4, Funny)

    by VirusEqualsVeryYes (981719) on Sunday August 05, 2007 @04:46AM (#20119641)

    It said an investment of $800 million to $1 billion could produce more than 100 gigawatts of electricity
    Cool. Now all we need is 83 flux capacitors.
  • Huh? (Score:4, Informative)

    by jawtheshark (198669) * <slashdotNO@SPAMjawtheshark.com> on Sunday August 05, 2007 @04:46AM (#20119643) Homepage Journal

    A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant.

    I think they should go on a trip to Iceland... Frankly [wikipedia.org]...

    • Re: (Score:2, Funny)

      by Anonymous Coward

      A Swiss company is competing with another in Australia to be the first to commercially develop a geothermal power plant.

      I think they should go on a trip to Iceland... Frankly...

      If they really want to see something interesting, they should descend into the crater of Sneffels [wikipedia.org] which the shadow of Scartaris touches before the calends of July. I have done this.

      Arne

    • by kaiwai (765866)
      Why go to iceland when there is New Zealand which already has working and commercially viable geothermal generation.
      • Re:Huh? (Score:5, Funny)

        by Curtman (556920) on Sunday August 05, 2007 @06:16AM (#20120001)

        Why go to iceland when there is New Zealand which already has working and commercially viable geothermal generation.

        Why go to Iceland, or New Zealand when you can go to Newfoundland and get pissed instead? Who needs to worry about electricity anyway, Alberta will take care of us.
  • Bullshit! (Score:5, Funny)

    by iamdrscience (541136) <michaelmtripp.gmail@com> on Sunday August 05, 2007 @04:47AM (#20119651) Homepage
    This will never work because, as we all know, the earth is hollow.
  • by wisebabo (638845) on Sunday August 05, 2007 @04:47AM (#20119655) Journal
    If an investment of $1 billion could "produce more than 100 gigawatts of electricity by 2050, equaling the combined output of all 104 nuclear power plants in the U.S." then we would all be getting our electricity (and probably all of our fuels would be made using electricity) from geothermal sources.

    Since I have some faith in studies from M.I.T. it seems like the writers are off by a few orders of magnitude. Probably they meant $800 billion to $1 trillion?
    • by xeno-cat (147219) on Sunday August 05, 2007 @08:37AM (#20120703) Homepage
      Even with your numbers, for the cost of the USA's war on Iraq we could have clean safe energy forever.

      Kind Regards
    • "Probably they meant $800 billion to $1 trillion?"

      So you're saying if we had just invested in Geothermal power instead of the war in Iraq (http://www.boston.com/news/nation/articles/2007/0 8/01/analysis_says_war_could_cost_1_trillion/) then not only would we not be in a quagmire in Iraq, but we would no longer have to be so involved in the political process in the middle east? Imagine if the amount of money going to that region was halved. The political power of people who are not at all friendly to the
  • Just 40% They say.. (Score:5, Informative)

    by Yazeran (313637) on Sunday August 05, 2007 @04:50AM (#20119673)
    Well they may be right that just 40% of the heat flow through the continental shield of the US may meet the energy demand 56k times over, the ticklish part is extracting the energy in an economic way. So far the only places where geothermal energy is usable is near active Volcanic areas where the geothermal gradient is steep enough to allow high temperatures near the surface and thus a high enough energy density to make the investment profitable (Think Iceland and California). All the other places the heat flow is too low to be usable for anything else than house heating.

    Another thing one must address is that the heat flow can only be used where permeable strata exists in the ground making it possible to circulate water to extract the heat. In places with crystalline bedrock, the heat flow can not be used.

    Yours Yazeran

    Plan: to go to Mars one day with a hammer.
    • by mochan_s (536939)

      One word.

      DRILL

      • Re: (Score:3, Insightful)

        by Ex-MislTech (557759)
        An extension of the word 'drill' , some old oil wells are fairly deep,
        and some of them are played out, ie. dry wells.

        They might make good exploratory candidates as the first 16,000+ feet is
        already drilled on a lot of dry holes.

        Some are deeper: ( over 4 miles down )

        Deepest well ( in california )(dry hole):
        Total depth: 24,426 feet (Point of Rocks)
        Year drilled: 1987
        County: Kern (Sec. 29, T.30S., R.23E.)
        Operator: Occidental of Elk Hills, Inc.
        Well name: 934-29R
    • Another thing one must address is that the heat flow can only be used where permeable strata exists in the ground making it possible to circulate water to extract the heat. In places with crystalline bedrock, the heat flow can not be used.

      In cold regions, near the ocean, like Canada's arctic, the sea is much warmer than the ambient temperatures which go as low as -50C. A heat pump from the ocean to buildings is quite a feasible way of exploiting geo-thermal power. One lays a pipeline instead of drilling do

      • by JDevers (83155)
        Maybe not as much as you think. I haven't done the math, but 2-5C water can carry off a LOT of heat, maybe more than -50C air.
    • low heat flow... (Score:2, Insightful)

      by Khyber (864651)
      "All the other places the heat flow is too low to be usable for anything else than house heating."

      Stirling engine?
    • Re: (Score:3, Interesting)

      by Ex-MislTech (557759)
      I think a better and easier way would be to capture the
      heat from the thermal vents on the sea floor, no drilling.

      http://en.wikipedia.org/wiki/Hydrothermal_vent [wikipedia.org]

      Would it be easy, no probably not,

      Would it be easier and cheaper than drilling every ten years a new hole, most likely.

      • Re: (Score:3, Insightful)

        by jcr (53032)
        Better still to use ocean water as a heat sink, and run a stirling cycle engine on the heat difference between surface and deep water temperatures. Bringing hot water up from the vents is a lot more trouble.

        -jcr

    • The numbers given are someones imagination. Total world power consumption is 15 TW [wikipedia.org] (there is a link to a DOE report in wiki). The total world geothermal heat flux [agu.org] is 44.2 TW (including the crust under oceans).

      Of course to some extent this heat can be "mined". The crust is a good heat insulator so it takes ages for the heat to escape the Earth. By drilling and pumping water, one can extract this heat quicker thus increasing the flux. But then, it's no longer a renewable source and it's not going to be vir

  • Ick, measurements (Score:5, Insightful)

    by Anonymous Coward on Sunday August 05, 2007 @04:58AM (#20119699)

    A study released this year by the Massachusetts Institute of Technology said if 40 percent of the heat under the United States could be tapped, it would meet demand 56,000 times over.

    Why do science journalists insist on giving human-unfriendly numbers like this? Is 40 percent feasible? No. Does 56,000 times hold any special significance? No. So why don't they say that 1% would meet demand 1,400 times over? It's a lot more realistic and more comprehensible for readers. Or why don't they say that the USA need only tap a thousandth of a percent of its heat to more than completely power the country? That's more relevant.

  • I'm not of the global-warming alarmists, but if you take stuff from a layer that's beneath you, and you pump it to a layer that's above you (which is what you do with coal, oil, uranium, and geothermal power plants) then you always change something in the environment. You displace heat. Or potential heat. Or waste products from heat. In other words, there's no way that this has no impact on the environment, it just has a lot _less_ impact on the environment.
  • "could fill the world's annual needs 250,000 times over with nearly zero impact on the climate or the environment"

    Apparently, scientists don't realize that the construction and maintenance of power plants and power transmission infrastructure has an environmental impact.
    • If only they were Rocket scientists, then they would have known.
    • Re: (Score:3, Interesting)

      by bmo (77928)
      "Apparently, scientists don't realize that the construction and maintenance of power plants and power transmission infrastructure has an environmental impact."

      Sharpening a stick and running after Bambi has an environmental impact. The construction of factories, power transmission, aluminum smelting and other stuff for the fabrication of my Cannondale bicycle has an environmental impact. Your criticism in this regard is knee-jerk unthinking stupidity. You're like the SUV driving "friends of the environmen
  • by Mogster (459037)
    but Wairakei here in NZ is a geothermal power generator http://en.wikipedia.org/wiki/Wairakei [wikipedia.org]
    It uses the natural geothermal activity local to the region.
  • actually I live less then half a mile from a Geothermal system:
    http://www.dti.gov.uk/energy/sources/renewables/r e newables-schools/case-studies/geothermal/page22986 .html [dti.gov.uk]

    I feel a dubious sci-fi film about sucking all the heat away from the Earth and the planet breaking up coming along (the Core 2?)... surely there must be some side effects?
  • The numbers (Score:5, Interesting)

    by el_flynn (1279) on Sunday August 05, 2007 @05:40AM (#20119853) Homepage
    TFA says the goal of the project is nice, but cost is a big barrier. "A so-called hot rock well three miles deep in the United States would cost $7 million to $8 million, according to the MIT study. The average cost of drilling an oil well in the U.S. in 2004 was $1.44 million, according to the U.S. Energy Information Administration."

    Yea, so that's about six times more expensive. But wouldn't the savings be much more in the long run? And more "environmentally friendly"? After all, according to http://www.globalissues.org/Geopolitics/ArmsTrade/ Spending.asp#USMilitarySpending [globalissues.org] US military spending was over $570 Billion in 2006. So why not spend, oh, say one percent of that figure to go towards coming up with clean energy?
    • Re: (Score:3, Informative)

      by Solandri (704621)

      "A so-called hot rock well three miles deep in the United States would cost $7 million to $8 million, according to the MIT study. The average cost of drilling an oil well in the U.S. in 2004 was $1.44 million, according to the U.S. Energy Information Administration."

      Yea, so that's about six times more expensive. But wouldn't the savings be much more in the long run? And more "environmentally friendly"?

      Oil wells in the U.S. are incredibly non-productive. People always think of oil wells as the geysers t

      • Re: (Score:3, Insightful)

        by wytcld (179112)

        That's assuming you could extract as much energy-dollars from a hot rock well as from an oil well (can't find any numbers on this, but it can't be much higher or the oil companies would be all over this

        There are several things you're missing in this analysis. First, the technology is not fully there yet - that's what the MIT panel said would take $1 billion and 10-15 years to develop. Second, any given reservoir of oil has a set, fairly short, lifespan. The geo-thermal source has an effectively infinite lif

        • by Solandri (704621) on Sunday August 05, 2007 @12:42PM (#20123103)

          Beyond that, oil companies may have no interest in developing a resource that would devalue their existing oil wells, and their leases on the oil fields beneath them. Geo-thermal power would be the monopoly of no country, no region.
          The problem with your conspiracy theory is that it involves a developing technology which the oil companies are perfectly suited to take advantage of (that was rude of you to selectively edit this out when you quoted me). They are the foremost experts at evaluating underground geology, drilling, getting liquid up from the bottom of a well, and sending liquid back down into a well. If they decided to invest in developing geothermal technology now, there is no way anyone else could catch up to them, and they would insure that they control the gateway to an (effectively) infinite energy source. They'd have to be crazy not to do it and risk someone else taking the lead from them. Unless there are other factors hindering the idea.

          Another thing to keep in mind is that with an effectively infinite energy source (with non-infinite power output), lower cost does not automatically mean lower profit. The laptop I'm typing on probably has more processing power than all the computers in the world back in 1975 combined, but does that mean my laptop is the only computer that was sold last year? No, Intel and AMD are selling more processors than they ever have. Lower energy cost just means people would come up with more ways to use energy, not continue to use the same amount of it.

          It would probably bankrupt all existing car manufacturers, since electric-car competitors can be nimbler if small, and would need very little from currently patented automotive tech.
          Hardly. Transportation energy sources have several requirements to which gasoline is well suited. Cost, high energy density (both volumetric and weight), ease and speed of distribution (refueling or recharging), and safety are some that come to mind. A cheap energy source like geothermal would take care of the cost requirement, but energy density (range) and distribution (time to recharge) would still remain a huge hurdle to electric vehicles. Also, most existing car manufacturers are at the forefront of electric vehicle development, and if they aren't they'd just buy up any electric car competitors to insure they stay competitive.

          the technology is not fully there yet - that's what the MIT panel said would take $1 billion and 10-15 years to develop.
          Right, which is why this is, as I asserted, a political problem; not one of oil companies conspiring to hold back technology.
  • geothermal is nothing but a pipe dream that gets dragged up every couple of years.

    a geothermal power plant is fundamentally flawed because your attempting to build a static structure on ground which is moving all the time, and it's geological activity is the very thing you need it for. the vast majority of such sites where there is enough thermal activity to make it worth while it would be too dangerous to put a power plant, and you can't just have a couple of power stations supplying the world.

    any sugges

    • Just how would it be too dangerous to put a power plant in a place with high geothermal activity? It's not as if there are going to be concentrated supplies of radioactive materials there, or even tanks of fuel oil or gas. Just steam. And the motion you speak of is quite small; we're not drilling into a lava flow or the earth's core.
      • by timmarhy (659436)
        geothermal activity means a much higher potential of earth quakes, a power plant is a hugely complex and dangerous environment - not a great place to put one. as i said, there are limited places where it can be done, but really it's not a solution to our power needs. It could service a local area very well though. but replacing all nuclear reactors with it is just rubbish.
    • Re: (Score:3, Insightful)

      by yndrd1984 (730475)
      your attempting to build a static structure on ground which is moving all the time

      WTF? What's moving?

      too dangerous to put a power plant

      Right, cause all of Yellowstone is as dangerous as Mt. St. Helens.

      any suggestion of digging great big holes is nonsense as well

      Since the big holes are already working quite well, I think you're full of it.

  • by Ninja Engineer (224395) on Sunday August 05, 2007 @06:08AM (#20119957)
    OK, so who let the morons out of the bag? The benefit of geothermal energy is not to reduce the amount of heat energy rejected into the envronment. ALL of the energy we use ends up there anyway. Thermodynamics and such, I won't bore you with the details.

    But every ton of CO2 released into the atmoshere has a devastating effect on our lives. Not that CO2 is poisonous, but if significantly effects the absorption of solar energy. Why do you think there are record floods in South Asia, the polar ice cap is melting and huricane season is no longer simply interesting. It is because the condition of our atmosphere is changing.

    Power produced by geothermal energy does end up producing heat. But it has an almost unnoticeable effect on our environment, and when it is shut off, its effects are shut off. This is absolutely not the case with fossil fuels, especially coal.

    So get to know the science, and be afraid. Be very afraid.
    • by timmarhy (659436)
      "every ton of CO2 released into the atmoshere has a devastating effect on our lives"

      OH PLEASE!!!! I can't stand the stupid greenhouse gas man made global warming rubbish being forced down my throat any longer!

      C02 is a very minor greenhouse gas, with there being no substantial evidence out there that c02 drives climate change.

      Here's a little science for you - the severity of our weather is determined by the tempature difference between 2 air masses, if the poles melt and the avgerage temperature increases

      • Re: (Score:2, Insightful)

        Please wake up. The science is proven. Computer models of the earth's atmosphere correspond extremely well with what is happening in real life. They prove the devastating effects of CO2 emissions. The denial of extremely strong proof might be macho cool, but it shows only a politician's understanding of the world. This is not alarmist crap.

        I strongly recommend a reading of "The Weather Makers" by Tim Flannery. Please read it. Please weigh the evidence provided. Then see if your opinion remains as-is, or if
      • C02 is a very minor greenhouse gas,

        Wrong:

        Despite the low concentration, CO2 is a very important component of the Earth's atmosphere because it absorbs infrared radiation at wavelengths of 4.26 m (asymmetric stretching vibrational mode) and 14.99 m (bending vibrational mode) and enhances the greenhouse effect to a great degree

        Source: Wikipedia.

        Wikipedia's source:
        http://www.amazon.com/First-Course-Atmospheric-Rad iation/dp/0972903305/ref=sr_11_1/103-2633496-84110 35?ie=UTF8&qid=1186318261&sr=11-1 [amazon.com]

        Here'
        • by timmarhy (659436)
          your quoting wikipedia which loses you most of your credibility right away on this issue, but then you proceed to cite wiki's source as a link to an amazon book sale? how the hell does that prove anything, do you expect me to buy the fucking book to double check?

          while it is correct that C02 does enhance the greenhouse effect, a point i didn't dispute, "to a great degree" is up for debate. compared to water vapour? compared to the SUN?

          and your kidding me, do you really need a source for air masses of diffe

    • But every ton of CO2 released into the atmoshere has a devastating effect on our lives.
      Really? It does? What exactly? Other than a lot of handwaving, media hysterics and politicians threatening to bring the economy to a halt in various ways I'm at a loss to see any significant effect (never mind a devastating one) on my life.

       
      • by Goaway (82658)
        How about you go look at the results of an entire fucking field of science, you goddamn fool?
  • by Anonymous Coward
    The oldest (over a century) and largest (produces 10% of the world's entire supply of geothermal electricity) is still in Italy, Larderello [wikipedia.org]. It produces more than 500 MWe.
  • I thought for a long time how great geothermal must be, then I thought about the possible drawbacks and long term effects.

    For instance, ever heat glass up and shove it in a tub of water? It shatters. Rock 3 miles under the earth, under pressure from all the rock above it, and heated from the core is probably just as brittle as glass. The article did mention earthquakes.

    Also what effect would this have on the magma flows below the rocks? I would imagine a geothermal cooled area might create stalagtites ar
    • Re: (Score:3, Informative)

      by vrmlguy (120854)
      First off, there are no such things as "stalagtites". There are only stalactites (which hang tight from the ceiling) and stalagmites (which stand mightily on the ground); from your description I presume that you mean the latter. However, both are formed by dripping water, so perhaps you mean the tufa towers of Mono Lake [wikipedia.org]. But those formed underwater and were only exposed when Los Angeles started diverting water from nearby rivers and the lake's water level fell. But no matter what you mean, these proje
  • Is it some left-over effect from when the Earth was formed, and thus subject to forever growing colder? Or is it from some effect that will keep on replenishing the heat?

    Also, does anything bad happen if we accelerate the cooling of the core?
    • Small space, high pressure. The pressure is caused by gravity -- the weight of all the stone on top of it. (The same thing causes nuclear fusion in the Sun.) It's not going to go away unless we forget to pay the gravity bill.
      • by plnrtrvlr (557800)
        Ummmmmmmm, no. The earth's core is hot mostly because of the decay of radioactive isotopes within the earth's core: http://www.physorg.com/news62952904.html [physorg.com] "the vast majority of the heat in Earth's interior--up to 90 percent--is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. These isotopes radiate heat as they shed excess energy and move toward stability. "The amount of heat caused by this radiation is almost the same as t
    • The core is a big spinning ball of hot metal. It's metal, so it's affected by magnetic fields. The sun, being a gigantic nuclear reaction, outputs tons of radiation; from your nuclear physics class, you should recall that small scale nuclear explosions produce a significant electromagnetic pulse. Large scale nuclear reactions also produce a significant electromagnetic pulse; the field force from the sun, coupled with the rotation and orbit of the earth, cause forces on the metal in the earth's core that
  • Waste of time. You need to turn water into steam to drive a turbine at what efficiency? With a big enough Sterling engine, I can achieve Carnot efficiency (theoretical perfect heat engine, absolute best efficiency possible in a perfect no-loss universe is 50% heat->motion conversion). Of course, my Sterling engine will run from the heat of the open air versus the 10C of 10 meters down in the ground; but a bigger temperature difference means better efficiency overall (improve efficiency: Colder cold s
  • Surely if the Earth's core is cooled too much due to excessive abstraction of geothermal energy, it will eventually solidify, shrink and start rattling around like an old walnut in its shell? And what if it bursts through? Come to think of it, even before that happens, there's a goodly-sized risk that the outer crust will be able to move independently with respect to the centre of mass, which will play merry havoc with the seasons.
  • I'd say its a pretty crappy article.

    The Ozzy company in question is Geodynamics and you can find their web site here: http://news.yahoo.com/s/ap//ap_on_sc/drilling_for_ heat;_ylt=AjvFzIDtqIn2aRl98jpXkE.s0NUE [yahoo.com]

    Their website has a good description of the progress and the problems they have encountered. I looked at investing in the company a few years back. So this isn't even current news.

    The _real_ problems have not yet surfaced. There are two (2) major issues.

    1) The amount of water one needs to push thro
    • I clipped the correct one! Contents were from the worng page! Blame firefox. Blame me for not checking this before I posted the comment.

      Geodynamics website can be found here: http://www.geodynamics.com.au/IRM/content/home.htm l [geodynamics.com.au]

      One needs to look closely at the projected economics.

      It said an investment of $800 million to $1 billion could produce more than 100 gigawatts of electricity by 2050, equaling the combined output of all 104 nuclear power plants in the U.S.

      Bullshit!

      A gigawatt power plant costs in
  • by plnrtrvlr (557800) on Sunday August 05, 2007 @08:12AM (#20120549)
    I've seen too many comments about the "effect this would have on magma under the earth if we cool it this way." The answer to these questions is that for a long long time, we'd have virtually no effect. The scale of human activity is just to small compared to the mass of the earth -the heat source for this power generation method. Go back to school and look at the graphics that show just how thin of an area the crust occupies on the earth. http://iga.igg.cnr.it/geo/what-is-for%20IGAnew_fil e/image038.jpg [igg.cnr.it] Now imagine for yourself just how thin of an area human activity would impact. The heat being used in these systems is not coming directly from magma, but instead is coming from heated rock far above those layers in the earth: heat that is already being transferred to the surface. The worst case scenario is that we might be able to "overbuild" and lower the thermal gradient for a time in a given area. In a case like this, the worst that would happen is that we would have to shut down the power plant for a time until the heat radiating up from deeper in the earth was allowed to build up again to a point where the gradient became economical for the power plant to run again. We are talking about using heat from solid rock, miles above a magma pool..... rock that is hot because of heat radiating to the surface from the earths core. We would be giving a small percentage of that heat a fast track to the surface.

    That said, I am sure that someday in the distant furure, such concerns would be warrented. I can forsee a day when the power needs of the earth and the technology is such that we would be tapping heat more directly from the mantle or core in amounts that we might be able to affect the magnetosphere by cooling the mantle/core significantly. This is not a problem for these projected plans. I would be doubtful of our ability to cool even a localized area enough that we could accomplish something like "eliminate the possibility of the Yellowstone supervolcano erupting." We have to keep in mind the scale of our activities compared to the size of the earth. Our ability to communicate only makes the earth seem to be small....

    Finally, on the subject of heating the earth: all electricty generation and consumption creates heat. We take fossil fuels from deep inside the earth and burn them, generate electricity and consume it, converting it back to heat as we do. This is all heat that would not have otherwise ever been found on the surface of the earth. Or we can take heat that is rising to the surface of the earth anyways, fast track it to the surface, generate electricity and do the consumption/conversion thing. Yes, we bring heat to the surface, but since it was on its way to the surface anyways, it seems a no brainer to me.

  • The Aussie project, at least, is using heat that's been created by natural radioactivity and trapped by specific geological formations, which only requires a drill-hole of two or three kilometres. This is well (ahem) within the capability of existing oil and exploration drilling rigs.

    Without these favourable conditions, you'd be drilling far deeper to get the required temperature differentals, which would require entirely new drilling tools and complicate the whole process.

  • Every Coal, Nuke, Natural gas, and even Wind plant is made via a manufactuering line. It allows the costs to be dropped TO 50 or even 10% of the other costs. Not even GE power makes a geothermal line (though they will be happy to produce a VERY expensive one for you).
    Geothermal plants are much cheaper to run than Nuke, Coal or gas plants. Once the upfront costs drop for them, then these will be put in places like the western USA where we could easily power the west and even midwest. But once these are sta

If the code and the comments disagree, then both are probably wrong. -- Norm Schryer

Working...